• Follica Inc., of Boston, raised $5.5 million in a Series A round led by Interwest Partners, with participation from PureTech Ventures. That funding is expected to take the company through a clinical proof-of-concept study of adrogenetic alopecia for hair loss. The company also has programs in skin and other follicle-related indications.

• Helicos BioSciences Corp., of Cambridge, Mass., closed a $20 million senior secured credit facility with GE Healthcare Financial Services. Helicos received $10 million under the new facility Dec. 31, and has the ability to draw down the remaining $10 million by June 30. The company, which develops genetic analysis technologies for research, drug discovery and diagnostics, intends to use the funds to support working capital and commercialization efforts.

• OSI Pharmaceuticals Inc., of Melville, N.Y., priced a private placement of $175 million aggregate principal amount of 3 percent convertible senior subordinated notes due 2038 and also granted purchasers a 13-day option to buy up to an additional $25 million. Sale of the notes is expected to close Jan. 9. OSI plans to use proceeds to fund repurchases of about 1.5 million shares of common stock, to repurchase or otherwise retire its 3.25 percent notes due 2023 and for general corporate purposes.

• Pharmos Corp., of Iselin, N.Y., completed an initial closing of a private placement of its 10 percent convertible debentures due November 2012, issuing $4 million principal amount of debentures and receiving gross proceeds in the same amount. Purchasers consisted of certain existing investors, namely Venrock Associates, New Enterprise Associates, Lloyd I. Miller III and Robert Johnston. A second closing is targeted for no later than 45 days from the date of the initial closing. Proceeds will be used for working capital, including the ongoing Phase IIb trial of dextofisopam in irritable bowel syndrome.